Telephone-switchboard system and ann unciator



P atented Apr. 4,1899.

G BpBUDGEBS. TELEPHONE SWITCHBOARD SYSTEM AND ANNUNCIATOR.

(Application filed Apr. 21, 1598.

{No Model.)

JNVEIVTOR WITNESSES NITED STATES PATENT OFFICE.

GEORGE BRANNER RODGERS, OF KNOXVILLE, TENNESSEE.

TELEPHONE-SWITCHBOARD SYSTEM AND ANNUNOIATOR.

SPECIFICATION forming part of Letters Patent No. 622,268, dated April 4, 1899.

Application filed April 27, 1898. Serial No. 678,950. (No model.)

T 0 aZZ whom it may concern.-

Be it known that. I, GEORGE BRANNER RODGERs,a citizen of the United States,residing at Knoxville, in the county of Knox and State of Tennessee, have invented certain new and useful Improvements in Telephone- Switchboard Systems and Annunciators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to telephone-switchboards, and particularly to annunciators and the circuits acting in connection therewith. Heretofore annunciators have been employed in which a shutter at the central office automatically dropped when the particular substation to which the annunciator related sent in a call, the restoration of the annunciator being automatically accomplished, but against to restore the aununciators with the resultant annoyances due to ind uction-currents created thereby. Another disadvantageous circumstance in connection with the restoration of some annunciators lies in the fact. that such restoration necessitates some extra motion on the part of the operator which would otherwise be unnecessary.

In my invention I have provided an annunciator and a mode of connecting it to the line-circuit whereby it is necessary to emhave constructed an annunciator havinga pair of line or calling coils symmetrically but alternately arranged on a suitable base-piece, to which base-piece is centrally pivoted an armature free to swing from one pair of magnets to the other. Attached to the armature is ashutter bearing a number or other symbol, which shutter is turned into View of the operator by the action of the armature when a calling-current is sent through the line or calling coils and which is turned out of view when the position of the armature is changed by the passage of a current through the restoring-coils. Instead of placing an extra spring member in the spring-jack to switch in the restoring-current to the annunciator I provide a third or additional anvil in connection with the operators ringing-button, so that in the act of ringing up the substation called for the operator automatically closes the circuit from the generator through the restoring-coils of the annunciator, and thus causes the armature with its attached symbol-bearing shutter to swing to restored position. At the same time I provide means whereby the operators telephone may be put in connection with the calling substation without the use of the usual listening-jack, the operator being required only to insert the plug in the spring-jack of the calling-substation and press the listening-button.

I have illustrated one form which my invention may assume in the accompanying drawings, forming part of this specification, in which Figure 1 is adiagrammatic view showing a calling-station connected by a line-circuit with an annunciator and a terminal spring jack in theswitchboard of the central station and a plug-circuit for uniting said callingstation with any other desired substation. Fig. 2 is a plan view of the annunciator; Fig. 3, a front elevation of Fig. 2 with the shutter in calling position. Fig. 4 is a side View of Fig. 3, and Fig. 5 is a vertical sectional view taken on the line 5 5 of Figs. 2 and 3.

Like letters refer to like parts throughout all the views.

Referring to Fig. 1, A is the instrument at the substation, the parts being shown in calling position, and Bis the annunciator corresponding to the instrument A on the switchboard of the central office, hbeing the pair of .of the annunciator B out of circuit.

line or calling coils, and I) the pair of restoring-coils. S represents the spring member of the spring-jack, and p the plug of the plugcireuit for insertion into the spring-jack in response to initial-call signals, 1) being the corresponding plug at the opposite end of the plug-circuit.

0 represents the operators instrument, and L the listening-button, by pressing which the operators instrument may be included in the line-circuit. I

O is the clearing-out annunciator, in which 0 indicates the clearing-coils, and c the restoring-coils.

G represents the generator, and R the operators ringing-button, by means of which the current from the generator G is switched onto the main line through the plug 1) to ring the bell of the subscriber, into whose springjack the plugp maybe inserted, the current at the same time passing through the restoring-coils of the calling-subscribers and the clearing-out annunciators. The spring-arms a TX of the ringing-button R normally rest against the anvils r 0"; but the circuits from these two anvils are opened when the ringingbutton R is pressed and the spring-arms 1" leave the said anvils. At the same time contact is made between the springs a and the anvils 1" 0' r establishing their respective circuits. At the listening-button L the anvil-points n n are normally in contact, permitting the current to pass without entering the operators instrument 0; but upon pressing the button L the springs m on contact with the anvils -1tn, compelling the current to pass through the operators instrument 0. hen a call is sent in from substation A, the circuit is com plete through the line a a, calling-coils b, wire ct, spring-jack member S, and line a. Upon the operator inserting the plug 1) into the socket S of the spring-jack the spring member S of the jack is lifted off of the anvil q, thereby cutting the calling-coils The operator then presses the listening-button L, and circuit is closed from substation Athrough the line a, spring-jack socket S, sleeve of plug 1), spring 'r anvil 0", wire (I, coils 0, wire cl, spring m, anvil n, operators instrument 0, anvil n", spring m, metallic socket 70, which is in electrical connection with sleeve of plug 1), thence by wire d to spring 1", to anvil 0", wire (1 stem of plug 1), spring-jack member S, and line-wire a to substation A. It will be noticed that in this circuit there is no impedance due to the line-annunciator B, as its coils are entirely eliminated from the circuit, and that but two movements upon the part ofthe operator are necessary to put her in communication with substation AViz., inserting the plug 1) into the spring-jack and pressing the listening-button. Upon receiving from substation A directions as to the subscriber with whom he wishes to be connected the operator raises the plug 1) from its socket 7; and inserts it into the spring-jack of the subscriber whom she wishes to call.

She then presses the ringing-button R, thereby throwing the springs r 9 out of contact with anvils v" 0" and causing spring 7' to contact with anvil 0" and the spring TX to contact with anvils 7" 7 Circuit is now closed from the generator G through anvil 7', spring TX, sleeve of plug 1), spring-jack socket S, line a, wire a, restoring-coils Z), wire d, coils c of clearing-out annunciator 0, wires d and g to generator G. This circuit is closed only when the ringing-button R is pressed, and the currentthus passed through the restoringcoils b c of the line and clearing annnnciators restores the annuneiators to their non-indicating positions, as will be hereinafter more fully described. The pressure of the ringing-button not only closes a circuit from the generator through the restoring-coils Z) c of the annunciators, but also through the bell of the called station, as follows: generator G to anvil 0", spring a, anvil 9", wire (1, spring m, anvils n a, spring on, stem of plug 1), line-wires to called station, return over sleeve of plug 1), wire d, spring 9', anvil 0", wires 01 and g to generator G. It will thus be seen that in the act of ringing up the called sta tion the operator closes the circuit from the generator through the restoring-coils of the line and clearing-out annunciators, thus restoring the annnnciators without any movement on her part other than those usually employed, and that the arrangement of the system is such that no constant current from the generator is on the system. I am thus enabled to avoid the annoying induction-currents experienced when a constant generatorcurrent is employed,and I also accomplish the restoration of the annunciator without requiring the operator to make an y additional motion for this purpose.

While the operation of the general system just described is not dependent upon the employment of any particular form of annunciator, I prefer to use an annunciator which I have devised and which is illustrated in Figs. 2, 3, 4t, and 5, in which F indicates a baseplate suitably supported, as by cars f, by which it may be attached to the switchboard. Mounted upon this base F are the line-coils b and the restoring-coils Z), symmetrically arranged, so that a plane passing through the longitudinal axes of the restoring-coils will intersect, preferably at a right angle, a plane passing through the longitudinal axes of the line-coils. The soft-iron cores of all the coils are attached in any suitable manner, as by screws f, to the base-plate F, and at the opposite end are united to a plate it. An armature II is mounted to turn in aplane at right angles to the longitudinal axes of the coils. The particular means employed in thus mounting the armature is immaterial, it being only essential that it act readily in response to the attraction of the respective coils. I have shown the armature II as attached to a pin or arbor 71', passing through an opening in the plate t and resting on its pointed end h in a centrally-located depression in the base-plate F. The armature may be a plain bar, preferably of sufficient length to extend from core to core of the respective pairs of coils; but I have shown aform which I deem more desirable than the plain bar-that is, I attach to the plain bar and on each side thereof, near its ends, Wings or arms la, preferably bent or curved, so that when the armature H is resting over one pair of coils-as, for example, the line-coils bthe wings or arms 70 7c will extend toward and upon the opposite sides of the other coils, which in the example taken would be the restoring-coils 1). Attached to the armature H is a shutter J, which, as here shown, is at right angles to the plane of the armature and moves with the latter, describing an are around the pin h as a center. Upon the shutter J is a symbol, which may be the number of the substation to which the annunciator corresponds, here shown as the number 11. Suitable stops 1 o are arranged to limit the turning or swingingmovements of the armature within an are preferably a little less than ninety degrees, so that when the armature rests over one pair of coils the ends of two of the arms It It on the same side of the armature will be at unequal distances-from the core of the coil included between them. This will be seen by inspecting Fig. 2, where it is apparent that the stop '0 is so placed that the armature will be stopped thereby before it has quite reached a position at right angles to a line connecting the centers of the coils b. The result is that the ends of the arms or wings 70 are nearer to the coils 5 than are the ends of the arms or wings 7c", and when the armature is turned to the position shown in dotted lines, Fig. 2, it is stopped by the stop '0, with the ends of the arms or wings 7c nearer the coils b than are the ends of the arms or wings 7c. The result of this construction is that the armature always moves in the direction of the arm that lies nearest to the coil. Thus in Fig. 2 the armature will move in the direction to carry the shutter from full-line position J to the dotted-line position J, because the ends of the arms 70' are nearer the coils 1) than are the ends of the arms is.

The operation of the annunciator is as follows: The armature H normally rests over the restoring-coils b, with the shutter in the dotted-line position shown in Fig. 2, and when a call is sent in from the substation corresponding to the annunciator the current passes through the line coils b, magnetizing their cores, and these attract the armature. The armature then turns from the dotted-line position J to the full-line position J of Fig. 2 and carries the shutter to a position to display the symbol ll to the operator. By the insertion of the plug p in the spring-jack the line-coils b are cut out, and hence deenergized, and when the operator presses the ringing-button R the circuit from the generator G is closed through action of gravity, as is the case when shutters of the drop class are employed. It will be observed that the operations of the annunciator are accomplished without the use of a constant generator-current, without imposing any additional motions upon the operator for this purpose, and without complicating -the spring-jack by extra springs or other additional members.

-I wish it understood that my invention contemplates the use of either an alternating or direct current to accomplish the restoration of the annunciator, and while I have shown the annunciator as operated by a current from the same generator used in the plug circuit to supply the ringing-current for a called station it is evident that the ringing-button might switch in current from any other source to restore the annunciator, and I therefore wish it distinctly understood that my invention includes such use of additional currents.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is

1. In a telephone-exchange system, the combination of a connecting plug-circuit, an annunciator, a generator in a normally open circuit including the restoring-electromagnet of the annunciator, and means for simultaneously severing the plug-circuit, switching the generator into connection with one portion thereof and closing the normally open circuit, substantially as described.

2. In a telephone-exchange system, the combination of a connectingplug-circuit, a generator, an annunciator, a normally open circuit including the generator and the annunciator, a ringing-button, and means operated by the ringing-button to sever the plug-circuit, to close said open circuit, and to connect the latter to a severed portion of the former, substantially as described.

3. In a telephone-exchange system a lineannunciator having an actuating and a restoring coil, a spring-jack, a plug-circuit, means conducting a calling-current through the actuating-coilalone when the plug-circuit is disconnected. from the jack, a generator, a ringing-key, means opening the circuit through the actuating-coil upon the connection of the plug-circuit with the spring-jack, and means actuated by the ringing-key and closing the generator-circuit through the restoring-coil alone when said key is operated.

4. In a telephone-exchange system, the combination of a connecting plug-circuit, an antoo IIO

nunciator having line-coils included in a circuit with a substation and one member of a spring-jack, said circuit adapted to be opened when the plug is inserted in the jack, a generator, a circuit including the generator and restoring-coils of the annunciator, which circuit is normally open at two points one of which is closed by the insertion of the plug in the spring-jack, and means for closing said circuit at the other point, substantially as described.

5. In a telephone-exchan ge system,the combination of a connecting plug-circuit, a generator, an annunciator having a line or calling coil and a restoring-coil and a shutterbearing armature pivoted toswing from one coil to the other, a normally open circuit including the generator, the restoring-coil of the annunicator, and means for simultaneously severing the plug-circuit, switching the generator into conn ection with one portion thereof and closing the normally open circuit.

6. I11 a telephone-exchange syste1n,the combination of a connecting plug-circuit, a generator normally excluded from said circuit, a clearing-out annunciator, a line-annunciator, a normally open circuit including the generatorand the restoring-coils of both said annunciators, a ringing-button, and means operated by the ringing-button to simultaneously sever the plug-circuit to switch the generator into connection with a severed portion thereof and to close said normally open circuit, substantially as described.

7. In a telephone-exchange system, a subscribers line, a spring-jack, and annuneiator therefor, an actuating and a restoring coil for the annunciator, a plug-circuit, a generator,

and a key for severing the plug-circuit and connecting the generator to the forward portion of the plug-circuit and to the restoringcoil of the annunciator, substantially as described.

S. An annunciator having a pair of line and a pair of restoring magnet-coils, said coils bein g alternately arranged so that a plane passed through the longitudinal axes of the line-coils would intersect a plane passed through the longitudinal axes of the restoring-coils, an armature normally over one pair of coils pivoted to swing from one pair of coils to the other, and arms on opposite sides of the armature extending toward one pair of magneteoils when the armature rests over the other pair, and stopsliiniting the swing of the armature, substantially as described.

9. An annuneiatorhaving a pair of line and a pair of restoring coils, said coils being alternately arranged so that a plane passed through the longitudinal axes of the line-coils would intersect a plane passed through the longitudinal axes of the restoring-coils, an armature normally over one pair of coils pivoted to swingfrom one pair of coils to the other, arms on opposite sides of the armature and extending toward the magnet-coils of. one pair when the armature rests over the other pair, and means stopping said armature so that said arms are nearer to one side of said coils than to the other, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE BRANNER RODGERS.

\Vitnesses:

JOHN D. CALDWELL, JAS. I'I. WELCKER. 

